Brush lifter for electric motors or the like



April 17. 1928.

G. H. LELAND BRUSH LIFTER FOR ELECTRIC MOTORS 6R THE LIKE Filed March 22. 1926 'IIIIIIIIII IIIIIIIIIIIIIIIIIIII Patented Apr. 17, 1928.

UNITED STATES GEORGE E. LELAND, OF DAYTON, OHIO.

BRUSH LIFTER FOB ELECTRIC MOTORS OR THE LIKE.

Application filed March 22, 1926. Serial No. 96,509.

This invention relates to brush lifters for electric motors or the like.

One object of the invention is to provide a simple eflicient device for lifting the brush out of contact with the commutator when the brush is not functioning.

A further object of the invention is toprovide such a device which will leave the brush free for movement independently thereof when the brush is functioning.

Other objects of the invention will appear as the device'is described in detail.

In the accompanying drawings Fig. 1 is 1 a front elevation of a device embodying my on the line 22 of Fig. 1, showing the brush in its operative position; Fig. 3 is a side elevation of the brush lifting device showing the brush in its inoperative position; Fig. 4 is a section taken on the line 44 of Fig. 3; and Fig. 5 is a side elevation of the brush actuating arm.

In these drawings I have illustrated one embodiment of my invention and have shown the same as operated by a centrifugal device connected with the commutator, but it will be understood that the brush lifting device itself may take various forms and that its operation may be controlled in any suitable manner.

As here shown, the brush holder 10 is mounted on a suitable part of the' motor frame, as shown at 11, and is provided with a longitudinal guideway 12 in which Is slidably mounted a brush 13. The guideway 12 has an enlarged central portion extending lengthwise thereof in which is arranged a spring 14 which is confined between the brush 13 and a stop plate 15 arranged at the outer end of the guideway' and held in position b a plug or cap 16 threaded into the end 0 the brush holder, this spring serving to press the brush normally into contact with the commutator 17. Near its inner end the brush holder is provided in its front and rear walls with openings 18 and 19 which communicate with the respective edges of the guideway and in which are slidably mounted brush liftin members or clamping blocks 20 and 21. heseclamping blocks are carried by pins 22 and 23 which are slidably supported in inclined guideways 24 and 25 formed respectively in the front and rear walls of the brush holder. The ends of the pins extend beyond the side walls of the invention; Fig. 2 is a sectional view taken brush holder and are acted upon by springs 26 which are'so arranged that they tend to move the two pins, and consequently the two brush engaging members, toward each other and thus into clamping engagement with the brush, as shown in Fig. 3.

The positions of the brush engaging members are controlled by an actuating device which is here shown in the form of a lever 27 comprising two parallel parts or arms arranged on opposite sides of the brush holder, pivotally supported at their rear ends b the pin 23 and rigidly connected at their orward ends by a transverse bar 28. Each arm of the lever has formed,therein a cam slot 29 to receive the projecting ends of the pin 22 which carries the forward brush engaging member 20. These cam slots are so shaped that when the lever is in its innermost position, as shown in Fig. 2, the pin 22 will lie in the upper portion of the cam slot and will be thereby forced forwardly against the action of the spring 26, thus separating the two brush engaging members and either moving the same entirely out of contact with the brush or maintaining such a light contact between the members and the brush as not to interfere with the movement of the brush toward the commutator under the influence of the spring 14. Whenvthe lever is moved outwardly to the position shown in Fig. 3 the pin will enter the lower portions of the cam slots 29 and will thus be released from the influence of the lever or actuating member to such an extent that the spring 26 will be permitted to move the two brush engaging members into clamping engagement with the brush, the frictional contact resulting from this engagement being sufiicient to overcome the pressure of the spring 14. At intermediate points the two arms of the lever 27 are provided with other cam slots 30 into which project pins 31 rigidly mounted in the respective side walls of the brush holder. These slots 30 are so shaped and so arranged'with relation to the slots 29 that when the forward end of the lever is moved outwardly the inclined walls of the slots 30 will engage the pins 31 and thus force the lever as a whole rearwardly, and the lever will carry with it the pins 22 and 23 and willcause the latter to ride up the inclined walls of the slots 24 and 25,

thereby lifting the brush out of contact with the commutator. The slots are so shaped that the first portion of the outward movementof the lever will release the brushengaging members for movement into contact with the brush by the spring 26, and the continued outward movement of .the lever will cause the supporting pins for the two brush engaging members to move upwardly in the slots 24. and 25 and to carry the brush with them, thus moving the latter out of contact with the-commutator. When the forward end of the lever is again moved inwardly the lever as a whole is moved forwardly by the action of the pins 31 on the inclined slots 30 and the brushes are separated by the action of the walls of the slots 29 on the pin 22.

The actuating device or lever 27 may be operated in any suitable manner to control the position of the brush. Preferably a centrifugal operating device is provided for that purpose which will cause the brush to be moved into its inoperative position when the motor has attained a certain predetermined, speed. In the present drawings if have shown a centrifugal device similar to that shown and described in my copending application filed March 18, 1926; No. 95,579, and as this centrifugal device forms no part of the present invention it need not be here described in detail. Suffice it to say that it comprises a series of weights 32- arranged about the motor shaft and movable outwardly by centrifugal force. Each weight has a forwardly extending flange 33 adapted toextend into a channel 34 forming part of the connecting bar 28 of the lever. lihe flanges are arranged in circumferential aline ment one with the other and, when the centrifugal device is in either its extended'or contracted position, will rotate freely in the channels but the, inward or outward movement of the weights will cause the flanges to engage the inner or outer walls of the channel and thus move the lever in the direction in which the weights are moved.

While I have shown and described one embodiment of my invention 1 wish it to be understood that I do not wish to be limited to the details thereof as various modifications ma occur to a person skilled in the art.

aving now fully described my invention, whatI claim as new and desire to secure by Letters Patent, is:

1. In a device of the character described, a brush holder having a guideway and openings in opposite walls thereof, brush engaging members mounted in the respective openings, yieldable means acting on said members to move them into engagement with a brush in said guideway, an actuating device connected with said brush engaging members and having means to hold the same in inoperative position when said actuating device is in one position and to release the same for movement by said yieldable means when said actuating device is in another position.

mean-rev 2. In a device of the character described, a brush holder having a guideway and openings in opposite walls thereof, brush engaging members mounted in the respective openings, yieldable means acting on said members tomove them into engagement with a brush in said guideway, an actuating device connected with said brush engaging members and having means to hold the same in inoperative position when said actuating. device is in one position and to release the same for movement by said yieldable means when said actuating device is in another position, and means controlled by said actuating device to impart outward movement to said brush engaging members while they are in operative engagement with said brush.

3. In a device of the character described,

a brush holder having a guideway and openings in opposite walls thereof, brush engaging members mounted in the respective openings, yieldable means acting on said members to move them into engagement with a brush in said guideway, and a lever pivotally connected with one of said brush engaging members and having a cam surface acting on the other of said brush engaging members, said oam surface being arranged to hold said brush engaging members in inoperative position when said lever is in one position and to release said brush engaging members for movement by said yieldable means when said lever is in another position.

4. In a device of the character described, a brush holder having a guideway and openings in opposite walls thereof, brush engaging members mounted in the respectiveopenings, yieldable means acting on said members to move them into engagement with a brush in said guideway, a lever pivotally connected with one of said brush engaging members and having a cam surface acting on the other of said brush engaging members, said cam surface being arranged to hold said brush engaging members in inoperative position when said lever is in oneposition and to release said brush engaging members for movement by said yieldable means when said lever is in another position, and means for causing said lever to impart outwardly movement to said brush engaging members while they are in operative engagement'with said brush. i

5. In a device of the character described, a brush holder having 'a guideway to re-' ceive the brush and having openings in opposite walls thereof, the walls of said openings having slots, pins slidably mounted in said slots, brush engaging members carried by said pins and arranged in the openings in said brush holder for movement into and out of engagement with a brush in said guideway, sgrin s acting on said pins to move said rus engaging members into operative engagement wig 'saidbrush, a/

lever pivotally mounted on one of said pins and having a cam surface to engage the other of said pins, said cam surface being so arranged that when said lever is moved to one position said brush engaging members will be separted and when said lever is moved to another position said brush engaging members will be released for movement toward the brush by said spring.

6. In a device of the character described, a brash holder having a guideway to receive a brush and having openings on opposite walls thereof, brush engaging members movably mounted in the respective openings, means for-supporting saidbrush engaging members for movement toward and from said brush and for movement lengthwise of said brush, springs actingon said pins to move said brush engaging members into operative engagement with the brush in said guideway, a lever having pivotal connection with one of said brush engaging members and having a cam surface arranged to act on the other brush engaging member, said cam surface being so arranged that when said lever is moved to one position said brush en aging members will be caused to operativey engage said brush, and means for causing said brush engaging members to move lengthwise of said brush holder while in operative engagement with said brush.

7. In a device of the character described, a brush holder having a guideway and having openings in opposite walls thereof, the walls of said openings having inclined slots, pins slidably mounted in said slots, brush engaging members carried by the respective pins, springs actingon said pins to move said brush engaging members into operative engagement with a brush in said guideway, and a lever pivotally mounted on oneof said pins and having a cam surface to engage the other pin, said cam surface being so arranged that when said lever is moved in one direction said brush engaging members will be separted and when said lever is moved in the other direction said brush engaging members will be released for movement by said springs into operative engagement with said brush.

8. In a device of the character described, a brush holder having a guideway to receive the brush and having openings in opposite walls thereof, the walls of said openings having inclined slots, pins slidably mounted in the slots of the respective openings and projecting beyond the side wall of said brush holder, brush engaging members mounted in said openings and carried by the respective pins, springs acting on said pins to move said brush engaging members into operative engagement with a brush in said guideway, a "lever ,pivotally supported at one end by one of said pins and having a cam slot into which the other pin projects whereby the movement of said lever will control the positions of said brushes, said lever having a second cam slot, and a fixed part carried by said brush holder and extending into said second cam slot to impart lengthwise movement to said lever.

9. In a device of the character described, a brush holder having a guideway to 'reoeive. a brush, and having openings in opposite walls thereof, the walls of said openings having inclined slots, pins slidably mounted in the slots of the respective openings and projecting beyond the respective side walls of said brush holder, brush engaging members movably mounted in said openings and carried by the respective pins, springs acting on said pins to move said brush engaging members into "operative engagement with a brush in said guideway, a lever comprising parts arranged on the respective sides of said brush holder, rigidly connected one to the other and pivotally supported by one of said pins, said parts of said lever having cam ,slots to receive the respective ends of the other in, said parts of said lever also having other cam slots, and studs carried by said brush holder and extending into the last mentioned slots.

In testimony WhGIGOfyI afiix my signature hereto.

GEORGE H. LELAND. 

